What does "jug" mean?

Additional senses

1. 2.A prison; a jail; a lockup. [Slang] Gay.
2. 3.To seethe or stew, as in a jug or jar placed in boiling water; as, to jug a hare.
3. 4.To commit to jail; to imprison. [Slang]
4. 5.To utter a sound resembling this word, as certain birds do, especially the nightingale.
5. 6.To nestle or collect together in a covey; -- said of quails and partridges.